Apparatus for the synthesis of ammonia



Oct. 9, 1928.

Original Filed Dec. 22. 1921 2 Sheets-Sheet INVENToR. @Zw Q v3 ATTORNEY`G. CLAUDE APPARATUS FOR THE SYNTHESIS 0F AMMONIA Original Filed Dec. 22.1921 I 2 Sheets-Sheet 2l lNVENTOR.

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Patented Octl 9, 1928.

UNITED STATES A ,1,686,799 PATENT OFFICE.

GEORGES CLAUDE, OF PARIS, FRANCE, ASSIGNOR, BY MESNE ASSIGNMENTS, T0LAZOTE INC., A CORPORATION 0F DELAWARE.

APPARATUS FOR THE SYNTHESIS OF AMMONIA.

Application led December 22, 1921, Serial No. 524,087. Renewed December17, 1926.

- This invention relates to apparatus for use in the-syntheticproduction of ammonia.

Inthe synthesis of ammonia, particularly with processes involving theuse of hyperpressures, the enormous working activity of the catalyzingmaterial brings about a relat-ively rapid deterioration of thismaterial, especially if, owing to fortuitous circumstances, the purityof the gas leaves anything to be desired or if, in consequence of faultyregulation or faulty internal arrangements, the internal temperaturebecomes too high.

It is, therefore, of the highest importance to be able with greatvfacility to renew the catalyzing material after deterioration of thesame. In this connection the extremely reduced dimensions of thereaction tubes for a given output consequent upon the extreme reductionof the volume of the gases and the enormous activity ofthe formation ofammonia, already assist in obtaining this result, but in a manner whichis still inadequate.

The present invention contemplates the provision of means which overcomethe dificulties hitherto experienced in the replacement of thecatalyzing material and which enable this replacement to be carried outquickly and with ease. The particular devices adapted for obtaining thedesired results in accordance with this invention are especiallyapplicable to the process which has been described in the c'o-pendingpatent application of Georges Claude, Serial No.

, 516.045 filed November 18, 1921.

The process described in the above mentioned application takes intoaccount the necessity of practically suppressing the elimination of theheat of reaction through the walls of the pressuresupporting tube, witha view to avoiding explosions through excessive expansion of theirinternal layers. The characteristic feature of this process consistsinfact in carrying away a quantity of heat equal to the heat of thereaction in the issuing gases and in abandoning the practice whichconsisted in bringing the entering gases up to the temperature ofreaction at the expense of the heat of the gases which have leftthecatalyzing material. The process according to the patent applicationsmentioned above consists, therefore, in introducing the gases into theenclosure where the reaction takes place Without having heated them, orbut little, Vand in causing them to circulate along an inner tubecontaining the catalyzing materialA and affording at each point athermal conductivity such that at the polnt in question the quantity ofheat removed from the gases in the inner tube is as exactly as possibleequal to that which is produced at this same point by the reaction.

According to the present invention in an apparatus for the syntheticproduction of ammonia the member constituting the closure of the outerpressure supporting tube carries a conduit which constitutes the exittube for the gases after reaction, the said conduit being continuedbeyond said member so as to project into thev nteriorof the pressuresupporting tube and carrying on its extended portion the inner tubecontaining the catalyzing material, With this construction of apparatusthe closure member and the inner tube may be easily and quickly removedfor effecting the renewal of the catalyzing materiaL In order that theinvention may be clearly understood and readily carried into eect thesame will now be more fully described with reference to the accompanyingdrawings in which:

Figure 1 shows in section one form of the improved -apparatus accordingto the present invention.

Figures 2 and 3 show details of the arrangement in which theclosure-member or head is provided with an interrupted screwthread.

In Figure 1 the -pressure-supporting tube H is made of a special metaladapted to resist the action of the gases present, for example of steelcontaining a high percentage of nickel, such as one of the steelscommercially known as A T G or B T G; this tube is insulated externallyagainst the conduction of heat as far as the vicinity of its head D;which is screwed'to the inside of the tube lI-I with an hermetic joint Fof the smallest diameter possible so as to. call into play the minimumamount of effort both for closing and for resistance to pressure.

The catalyzing material C is placed in an inner tube T having vanlexternal heat insulating coating E of decreasing thickness, and thereacting gases which enter through the orice A, which may be locatedupon the head D or laterally upon the tube H, circulate in the annularspace B around the heat insulated tube T-E. The tube T is conhead D towhich it is attached and, in order thereupon to replace the catalyzingmaterial, it suffices to remove the plug R.

It Will be seen that this replacing operation is effected easily andWithout having to interfere with the external tube H,l which is by farthe heaviest part of the apparatus and which may remain permanently inposition, together with its elect-ric heating circuits S, in itsinsulated receptacle, .and can thus be maintained Without difficulty atthe reaction temperature.

To facilitate the dis-assembly, the end of the tube H is provided, forexample, With tWo small Hat parts J which fit into a recess made in avery thick lxed metal plate K. This metal plate thus plays the part of acounter-k spanner When acting with a Spanner upon the head D. v v

The invention includes, furthermore, the facilitation of the renewal ofthe catalyzing material to the point of rendering such renevvals almostas simple asthe replacing of a projectile in a gun of large calibre.

In this connection it will be remarked that one of the consequences ofthe method of circulation of the gases hereinbefore referred to is thatthe temperature of the pressure-supporting tube H decreasesprogressively along its length, from the end Where the hot gasespenetrate into the catalyzing material and Where this temperature isequal to the reaction temperature up to the other end which carries thehead D Where this temperature but slightly exceeds the surroundingtemperature. Were the head also at a temperature only slightly raisedthen the conditions as re` gards tightness of the joint F, vand ofnongripping of the screw threads in case of frequent dismountings, couldbe satisfactorily complied with by maintaining good lubrication of thesrcew threads. In order to obtain this result it suiiices to arrange asfar as possible for the intimate contact with the head of the cold orslightly heated entering gases and to prevent as far as possible contactWith the f issuing hot gases. With this object the gases may be made topass out through a central tube L separated from the head by an asbestoslining M and hermetically sealed by means of a stuffing box M packedwith asbestos or by means of a countersunk joint.

The cold gases on the contrary enter in direct contact with the metal,through the oriice A and the annular conduit O Which distributes themsymmetrically in such manner as to prevent any inequalities oftemperature which Would deleteriously affect the tightness of the joint.The tube L through which the gases issue must be made of metal which iscapable of supporting their high temperature. The connection With thetube or steel coil for conducting these gases to the ammonia liquelieris effected by means of a connection N immersed -in Water. The head Dmay be made of a metal Which fits as Well as possible from the point ofviewof gripping of the screw threads, the metal of special type of whichthe pressure-supporting tube is formed; it may, for example, be made ofmild or semi-hard steel in the case Where the special steels mentionedabove are used for the tube H.

In order to quickly replace the catalyzing material, it Would hardly bepractical, after vhaving unscrevved the connected parts T D, to removethe used up material, refill the tube T with fresh non-formed material(i.e.notre duced by hydrogen), again screw up the connected parts T D inthe tube H and 4then form the catalyzing material. The present inventionprovides that, after exhaustion of the catalyzing material, theconnected parts T D are replaced by another identical' part alreadyformed in another supplementary external tube by means of hydrogen orpreferably by the small hyper-compressed gaseous residue stillcontaining hydrogen issuing from the last catalyzer tube of the plantdur-- ing normal Working.

In this latter case the ammoniacal gases produced may be sent on issuingfrom this supplementary tube into a sulphuric acid absorber and thefinal residue can be returned tothe hydrogen-making plant. As the outputof gas in this supplementary tube is very low, and as the effect of theinternal heat insulating lining E is less than that under conditions ofnormal output, it may happen that when the reduction is very advancedthe tube rises in temperature despite all the heating circuits being cutoli'. It Will suffice to reduce the pressure of the gaseous residuefeeding this tube by means of a regulating cock in order to successfullycontrol this tendency.

Under the conditions thus depicted even the unscrevving of the head Dbecomes a lengthy operation in consequence of the compulsory lengthofthe screwed portion, espe- .cially if the operation has to besimultanethat, on forcing in the tube T so that the head D goes home, arotation of one fourth or one Sixth of a revolution isfsuticient toeffect engagement of the male and femalethreads,

the rotation being effected for example byA the aid of a handlecontrolling through a tangent screw a toothed crown made in the head D;in this way'there can be crushed a veryv A and mounted in bearings X1,X2, X? and X4 on the plate K. These two screws V are controlled, forexample, byahandle P through gearing P which permits of a considerablereduction of the effort necessary for crushing the packing ring at F andfor obtaining the tightness.. More simply, by means of a handle atoothed lwheel mounted upon the axis of one of the twoscrews and engagngwith a second similar toothed wheel mounted upon the axis of the otherscrew may be caused to rotate direct. These same figures show that thehead D and the tube H are provided respectively with male and femaleinterrupted screw threads.

lVhen the head is in place it suffices to screw lthe gas inlet andoutlet tubes thereto by means of the connections A. and N, the latterbeing then immersed in cold water as has been explained.

Various changes may be made in the details of arrangements of the partsas hereinbefore described without departing from the invention orsacrificing any of the advantages thereof.

I claim:

l. An apparatus for the synthetic production of ammonia in which amember constituting a closure of the outer pressure supporting tubecarries a conduit for the gases, the said conduit being continued beyondsaid member so as to proj ectstraightforward into the interior of thepressure-supporting tube and carrying on its extended portion an innertube containing the catalyzing material.

2. An apparatus for the synthetic production of ammonia in which amember constituting a closure of the outer pressure-supporting tubecarries a conduit for the gases, the said conduit being continued beyondsaid member so as to project straight-forward into the interior of thepressure-supporting tube and carrying on its extended portion an innertube containing the catalyzing material, and means whereby the gasesthat are to undergo reaction are admitted into the space between theouter pressure-supporting tube and the inner tube at that end of theapparatus where the closure member is located.

3. An apparatus for the synthetic production of ammonia in which amember constituting a closure of the outer pressure-supporting tubecarries a conduit thermally insulated therefrom, which conduitconstitutes the exit tube for the gases after reaction, said conduitbeing continued beyond said member so as to project straight-forwardinto the interior of the:pressure-supporting tube and 'the gases afterreaction,

carrying on its extended portion an inner tube containing the catalyzingmaterial, and means whereby the gases that are to undergo reaction areadmitted into the space between the outer pressure-supporting tube andthe inner tube at that end of the apparatus where the said closurememberis located.

4. An apparatus for the synthetic production of ammonia in which themember constituting the closure of the outer pressuresupporting tube hasan inlet conduit passing therethrough and through which conduit thegases that are to undergo reaction are introduced into the apparatus soas to cool the aforesaid member, and said member also carrying a conduitwhich constitutes the exit tube for the gases after reaction, saidconduit being continued beyond said member so as to projectstraight-forward into the interior of the pressure-supporting tube andcarrying on its extended portion the inner tube containing thecatalyzing material, and means whereby the gases that are to undergoreaction are admitted into the space between the outer4pressure-supporting tube and the inner tube at that end of the apparatuswhere the closure member is located.

5. An apparat-us for the synthetic production of ammonia in which amember constituting a closure of t-he outer pressure-supporting tube hasan inlet conduit passing r therethrough and through which conduit thegases that are to undergo reaction are introduced into the apparatus soas to cool the aforesaid member, and said member also carrying a conduitthermally insulated therethrough which constitutes the exit tube forsaid conduit being continued beyond said member so as to projectstraight-forward into the interior of the pressure-supporting tube andcarrying on its extended portion the inner tube containing thecatalyzing material, and means whereby the gases that are to undergoreaction are admitted into the space between the outerpressure-supporting tube and the inner tube at that end of the apparatuswhere the closure member is located.

6. An apparatus for the synthetic pro-l duction of ammonia, comprisingan 4outer pressure-supporting tube, an inner tube containing theIcatalyzing material contained within the said outer tube, a memberconstitut-ing a closure of t-he said outer tube, said member and theportion of the outer tube with which it engages being constructed withmale and female screw threads of interrupted formation and means beingprovided for rotating t-he closure member into and out of engagement,and a. conduit which constitutes the exit tube for the gases afterreaction carried by the aforesaid member, the said conduit beingcontinued beyond said member so as to project into the interior of thepressuresupporting tube and carrying on its extended portion theaforesaid inner tube containing the catalyzing material.

7 An apparatus for the synthetic production of ammonia, comprising anouter pressure-supporting tube, an inner tube containing the catalyzingmaterial contained within the said outer tube, a member constituting theclosure of the said outer tube, said memj ber and the portion oftheoutertube' with which it engages being constructed with male and femalescrew threads of interrupted formation, and means being provided forrotating the closure member into and out of engagement, an inlet conduitpassing through the said member and through which conduit the gases thatare to undergo reaction are introduced into the apparatus so as to coolthe aforesaid member, and a conduit which consaid inner tube containingthe catalyzing ma.-

terial.

8. An apparatus for the synthetic production of ammonia, comprising anouter pressure-supporting tube and an inner tube containing thecatalyzing material contained Within the Said outer tube and attached bymeans such as lag-bolts to a member constituting the closure of the saidouter tube, said member carrying a conduit which constitutes the exittube for the gases after reaction, and said conduit being continuedbeyond said member so as to project into the interior of thepressure-supporting tube and carrying on its extended portion theaforesaid inner tube containing the catalyzing material.

9. An-apparatus for the synthetic production of ammonia, comprising anouter pressure-supportingtube, an inner tube cont-aining the catalyzingmaterial contained wit-hin the said outer tube, a member constitutingthe closureof the said outer tube, said member,

and the portion of the outer tube with which it engages beingconstructedwith male and female screw threads of interrupted formation,and means being provided for rotating the closure member into and out ofengagetuting the exit tube being continued beyond said member so as toproject into the interior of the pressure-supporting tube and 'carry-.ing on its extended portion the aforesaid inner tube containing thecatalyzing material, and additional means such as lag-bolts yforattaching the aforesaid innner tube to the closure-forming member. y

l0. An apparatus for the synthetic production of ammonia, comprising anouter pressure-supporting tube provided with an external heat-insulatingcovering and an elec-trical heatingcircuit within the said covering,

lsaid outer tubel being constructed and arranged so as to resist .thephysical and chem- -ical conditions to which it is subjected, an

inner tube containing the catalyzing material and constructed with Wallshaving a variable thermal conductivity along the length of said tube, amember constituting the closure of the said outer tube, said member andthe portion of the outer tube with which it engages being constructedwith male and female screw threads of interrupted format-ion, and meansbeing provided for rotating the closure member into and out ofengagement, an ,inlet conduit passing through the said member andthrough which conduit the gases that are 'to undergo reaction areintroduced into the apparatus so as to cool theaforesaid member, and aconduit which constitutes the exit tube for thegases afterreactionvcarried by but thermally insulated from the aforesaid member,the said conduit constituting the exit tube being continued beyond saidmember so as to project into the interior of the pressure-supportingtube and carrying on its extended portion t-he aforesaid inner tubecontaining the catalyzing material.

ln testimony whereof l amr my signature.

GEORGES CLAUDE.

